The invention is directed to a pump fiber with high luminous density for solid-state lasers with one or more pump light sources.
U.S. Pat. No. 5,127,068 discloses an arrangement for coupling a multi-emitter laser diode to a multi-mode optical fiber, whereby each emitter emits the pump light onto the laser crystal via an optical fiber. What is thereby disadvantageous is that only a low luminous density on the laser crystal is achieved as a consequence of the large fiber bundle diameter and, thus, the efficiency of the laser arrangement remains low. Another disadvantage of this arrangement is the involved and complicated coupling of the individual optical fibers to the emitters. Moreover, the power density is relatively low, since the fibers cannot be packed densely enough, and each fiber can only accept the power of one emitter. The power density lies approximately at 1 KW/cmxe2x80x3.
EP 0 632 551 A1, FIGS. 28 and 29 plus corresponding description, disclose a laser amplifier system wherein a laser crystal is pumped with a multiple mirror arrangement via a fiber bundle. In addition to the above-described disadvantage of the fiber bundle, a multi-mirror arrangement is required in the pump beam path of the laser, this being involved and complicated to manufacture. Further, such an arrangement is difficult to manufacture with adequate cleanliness and is difficult to protect against contamination during operation. As a result thereof, a short service life derives, particularly given high powers.
An object of the invention is to manufacture a more cost-beneficial laser arrangement with high output power, high efficiency and long service life that is simple to fabricate.
According to the present invention, a solid-state laser is provided having at least one pump light source with a plurality of laser diodes. An optical laser resonator with a laser crystal is provided whereby laser light generated in the laser diodes is coupled into the laser crystal. For generating a high luminous density of the laser light coupled into the laser crystal, the laser diodes of each pump light source are followed by a multi-mirror arrangement with which the laser light of the individual laser diodes is superimposed. A single waveguide is provided into which the superimposed laser light with high luminous density is coupled and transported to the laser crystal. The single waveguide is arranged behind the multi-mirror arrangement of each pump light source.